Abstract (EN):
In the present study, biosorption of Ni2+ by Na-loaded (raw algae treated with NaCl), algae Pelvetia canaliculata
Ochrophyta, was studied in a batch system. Kinetics and equilibrium experiments were conducted
at different pH values (2.0, 3.0 and 4.0). The metal uptake capacity decreased by decreasing the solution
pH, suggesting that competition exists between hydrogen ions, present in high concentrations at low pH
values, and metal ions. An ion-exchange model, considering two different binding sites, sulfonic and carboxylic
groups, was developed to describe equilibrium data. A mass transfer model, considering intraparticle
resistance was also developed to describe kinetics in a batch system. The release of sodium ions
during the uptake of nickel ions revealed that the biosorption mechanism involved ion-exchange
between sodium and nickel ions with a stoichiometrical ratio of 2:1. Nickel showed higher affinity to
the sulfonic groups than for carboxylic ones of algae biomass. Kinetic results show that hydrogen ions
diffuse faster as compared to nickel and sodium ions. The maximum uptake capacity of Na-loaded algae,
P. canaliculata, for Ni2+ was found to be ca. 100 mg/g at pH 4.0.
Language:
English
Type (Professor's evaluation):
Scientific
No. of pages:
8